Dosing regimens of oral bisphosphonates are inconvenient and contribute to poor compliance. The bone mineral density response to a once weekly delayed-release formulation of risedronate given before or following breakfast was non-inferior to traditional immediate-release risedronate given daily before breakfast. Delayed-release risedronate is a convenient regimen for oral bisphosphonate therapy.

Bone mineral density response to once weekly delayed-release formulation of risedronate, given before or following breakfast, was non-inferior to that seen with traditional immediate-release risedronate given daily before breakfast. Delayed-release risedronate is a convenient dosing regimen for oral bisphosphonate therapy that might avoid poor compliance.This 2-year, randomized, controlled, non-inferiority study assessed the efficacy and safety of a delayed-release (DR) 35-mg weekly oral formulation of risedronate that allows subjects to take their weekly risedronate dose before or immediately after breakfast. Results from the first year of the study were published previously (McClung et al. Osteoporos Int 23(1):267-276, 2012); we now report the final results after 2 years.Women with postmenopausal osteoporosis were randomly assigned to receive risedronate 5 mg immediate-release (IR) daily (n = 307) at least 30 min before breakfast, or risedronate 35 mg DR weekly, either immediately following breakfast (FB, n = 307) or at least 30 min before breakfast (BB, n = 308). Bone mineral density (BMD), bone turnover markers (BTMs), fractures, adverse events, and bone histomorphometry were evaluated.A total of 248 subjects (80.8 %) in the IR daily group, 234 subjects (76.2 %) in the DR FB weekly group, and 240 subjects (77.9 %) in the DR BB weekly group completed the 2-year study. After 2 years of treatment, BMD increases at the lumbar spine and total hip with the weekly DR doses similar to or greater than that with the IR daily dose. Decreases in BTMs were similar or significantly lower in the DR groups. Bone histomorphometry results did not differ among the DR weekly and the IR daily formulations. The three regimens were similarly well tolerated.Risedronate 35 mg DR weekly is as effective and as well tolerated as risedronate 5 mg IR daily, and will allow subjects to take their weekly risedronate dose immediately after breakfast.

This study showed that risedronate 150-mg once a month provides similar efficacy and safety at 2 years compared with risedronate 5-mg daily for the treatment of postmenopausal osteoporosis. This adds to the range of risedronate dosing options and provides an alternative for patients who prefer once-a-month dosing. Risedronate is effective in the treatment of postmenopausal osteoporosis in oral daily, weekly, or on two consecutive days per month doses. This 2-year randomized, double-blind, multicenter study assesses the efficacy and safety of a single risedronate 150-mg once-a-month oral dose compared with the 5-mg daily regimen. Women with postmenopausal osteoporosis were randomly assigned to receive risedronate 5-mg daily (n = 642) or 150-mg once a month (n = 650) for 2 years. Bone mineral density (BMD), bone turnover markers, new vertebral fractures, and adverse events were evaluated. The primary efficacy endpoint was the mean percent change from baseline in lumbar spine BMD after 1 year. Four hundred ninety-eight subjects in the daily group (77.6 %) and 513 subjects in the once-a-month group (78.9 %) completed the study. After 24 months, the mean percent change in lumbar spine BMD was 3.9 % (95 % confidence interval [CI], 3.43 to 4.42 %) and 4.2 % (95 % CI, 3.68 to 4.65 %) in the daily and once-a-month groups, respectively. The once-a-month regimen was determined to be non-inferior to the daily regimen. The mean percent changes in BMD at the hip were similar in both dose groups, as were changes in biochemical markers of bone turnover. The incidence of adverse events, adverse events leading to withdrawal, and upper gastrointestinal tract adverse events were similar in the two treatment groups. After 2 years, treatment with risedronate 150-mg once a month provided similar efficacy and tolerability to daily dosing and provides an alternative for patients who prefer once-a-month oral dosing.

Introduction: Risedronate has been shown to be effective in the treatment of postmenopausal osteoporosis when given orally in daily or weekly doses or on 2 consecutive days per month. This randomized, double-blind, multi-center study was designed to assess the efficacy and safety of a single 150 mg risedronate once-a-month oral dose compared with the 5 mg daily regimen.Methods: Women with postmenopausal osteoporosis were randomly assigned to receive risedronate 5 mg daily (n=642) or 150 mg once a month (followed by daily placebo) (n=650) in a double-blind fashion for 2 years. Study drug was taken on an empty stomach at least 30 min before breakfast. Bone mineral density, bone turnover markers, fractures, and adverse events were evaluated. The primary efficacy endpoint was the mean percent change from baseline in lumbar spine bone mineral density after I year.Results: 538 patients in the daily group (83.8%) and 556 patients in the once-a-month group (85.5%) completed 1 year. The mean percent change in lumbar spine bone mineral density was 3.4% (95% confidence interval, 3.03% to 3.82%) in the daily group and 3.5% (95% confidence interval, 3.15% to 3.93%) in the once-a-month group. The difference between groups was -0.1% (95% confidence interval, -0.51% to 0.27%). The once-a-month regimen was determined to be non-inferior to the daily regimen based on prospectively defined criteria. The mean percent changes in bone mineral density at sites in the hip (total proximal femur, femoral neck, femoral trochanter) were also similar in both dose groups, as were the changes in biochemical markers of bone turnover. The incidence of adverse events, adverse events leading to withdrawal, and upper gastrointestinal tract adverse events were similar in the 2 treatment groups. Both regimens were well tolerated; the percent of patients who withdrew from treatment as a result of an adverse event was 9.5% in the daily group and 8.6% in the once-a-month group.Conclusions: Risedronate 150 mg once a month is similar in efficacy and safety to daily dosing and may provide an alternative for patients who prefer once-a-month oral dosing. (C) 2007 Elsevier Inc. All rights reserved.